Lamp



Jan. 11, 1927. 3,614,027 R. GRAF LAMP Filed July 1 I 1925 Patented Jan.11, 1927.

UNITED STATES PATENT OFFICE.

RICHARD GBAF, OF SOUTH BEND, INDIANA.

LAMP.

Application filed July 1, 1925. Serial No. 40,782.

My invention relates to headlamps such as are used on automobiles.

The main object of the invention resides in the provision of a lampwhich while projecting an adequate and eflicient light so controls thelight as to prevent glare in the eyes of occupants of other vehicles orpedeserence to'the accompanying drawings and more particularly pointedout in the appended claims;

In the said drawing Figure 1 is a central vertical longitudinal sectionof a lamp embodying my invention.

Figure 2 is a rear elevation of the light shield of the lamp.

Like characters of reference indicate like parts in the various views.

Referring to the drawing 1 designates a m in cylindrical casing memberupon the re r end of which is screwthreaded a deep bell shaped rearcasing member 2 completing the casing. A deep forwardly facing cupreflector 3, preferably elliptical asshown, is positioned rearwardly iiithe casing and is provided with a forwardly facing electric lamp socketmounting 4. disposed on the focal axis of the reflector, in which ismounted for longitudinal adjustment along said focal axis a usualelectric lamp socket 5.

The adjustment of this socket is controlled from the exterior of thelamp casing by a usual adjusting means 6. A usual incandescent electriclamp 7 within the reflector is mounted in the socket 5. The reflectorhas an inner and outer focus, and the electric lamp is adjusted to theinner focus thereof. A condensing lens 8 is disposed at the forward endof the casing co-axial with the reflector to project the light from theelectric lamp and reflector and is mounted on the casing by a ring 9screwthreaded on the front end of the casing member 1 and clamping themargin of the lens between it and an internal flange 10 of the casingmember 1. The rear focus of the lens is disposed substantially at theouter focus of the reflector in order to project the concentratedreflected light together with the direct light from the electric lamp.

An opaque light shield 11 surrounding the focal axis of the lamp isdisposed Within the casing 1 and has a relatively small centrallydisposed aperture 12 substantially at the rear focus of the lens. Fromthis aperture the shield extends and enlarges rearwardly with aninterior generally frusto-conical reflecting surface 13 coaxial with thereflector and lens to the lip of the reflector. The reflector and shieldare provided with exterior circumferential flanges, designated at14,which are clamped in superposed relation between interior shoulders15 when the casing members are assembled. the flange 14 of the shieldcarrying rearwardly projecting pins 16 engaging in apertures of theflange 14 of the reflector and shoulder 15 of the casing member 2 toangularly position the casing member 2, the reflector and the shieldwhen assembled.

The aperture 12 being disposed substantially at the inner focus of thelens causes a real image thereof to be projected by the lens and byreason ,of this position of the aperture and the relatively small sizeof the same a relatively small sharply defined beam of intense lightfrom the electric lamp and reflector is projected by the lens.

The aperture 12 as shown is elongated horizontally, see particularlyFig. 2, Whereb the light is shielded to a greater degree a ove and belowthe focal axis of the lamp than at the sides thereof, and the lower edgeportion of the aperture is disposed nearer the focal axis of the lampthan the upper edge portion thereof whereby the light is shielded to agreater degree below the focal axis of the lamp than above the same, itbeing obvious that a reverse image of the aperture is projected by thelens.

The above referred to beam of intense light has a cross section of theaperture 12 reversed, and the upper portion thereof is substantiallyparallel with the focal axis of the lamp whereas the sides diverge to amaximum degree a'nd the lower portion of the beam divergesj't'o anintermediate degree. As a result the road'in front of a vehicle equippedwith the lamp is illuminated from side to side from a point adjacent thelamp forwardly though the intense beam does not extend upwardly farenough to lare in the eyes of occupants of other VQlllClGS orpedestrians.

The shield 1.1 has chordal interior reflecting surfaces 17 extendingrearwardly and outwardly from the upper and lower portions of theaperture 12 and merging with the generally frusto-conical interiorreflecting surface 13 of the shield whereby the upper and lower edgeportions of the aperture together with the side edge portions thereofare disposed in a common plane thoughthe rearward and outward extensionof the interior surface of the reflector is maintained throughout.

The interior reflecting surfaces 13 and 17 of the shield 11 serve notonly to reflect light indirectly back to the reflector but to reflectdispersed light from theelectric lamp and the reflector directly to thelens from which this light is projected as a dispersed nonglaring lightabout the aforementioned intense beam to further aid in the illuminationadjacent the lamp. In addition the light reflected from the reflectingsurfaces 13 and 17 serves to increase the brilliancy of the light imageat the aperture 12 with resulting increase in the brilliancy of theaforementioned intense beam.

Thus it will be observed that the light is conserved and projected sothat it is applied to the best advantage without glare and withconsequent efficiency and adequacy of light.

While I have herein shown and particularly described the preferredembodiment of my invention I do not wish to be limited to the precisedetails of construction shown as changes may readily be made withoutdeparting from the spirit of my invention, but having thus described myinvention I claim as new and desire to secure by Letters Patent thefollowing:

1. In a lamp of the character described the combination with a casingopen at. its front end, a forwardly facing cup reflector having an innerand an outer focus and mounted rearwardly in the casing with its outerfocus within the casing, an incandescent electric lamp at the innerfocus of the menace? reflector, and a condensing lens mounted forwardlyon the casing and positioned to pro ject the light from said reflectorand elec tric lamp with its rear focus substantially at the outer focusof the reflector, of an opaque light shield surrounding the focal axisof the lamp between said lens and said reflector and electric lamp andhaving a relatively small centrally disposed horizontally elongatedaperture substantially at the rear focus of the lens and having itslower edge portion disposed nearer the focal axis of the lens than theupper edge portion thereof, and extending and enlarging reap wardlytherefrom with an interior generally frusto-conical reflecting surfaceto the lip of the reflector and having chordal interiorreflectingsurfaces extending rearwardly and outwardly from the upper andlower poitions of said aperture and merging with said frusto-conicalsurface.

2. In a lamp of the character described, the combination of a casingopen at its front end, a forwardly facing cup reflector, an incandescentelectric lamp located in the axis of the reflector so as to have itsrays converged by said reflector at a point on said axis and forwardlythereof, a condensing lens mounted forwardl on the casing with its rearfocus substantially at the point of convergence of the rays, of anopaque light shield surrounding the focal axis of the lamp between saidlens and said reflector and electric lamp, and having a relatively smallcentrally disposed horizontally elongated aperture substantially at therear focus of the lens, and having its lower edare portion horizontaland disposed nearer the focal axis of the lens than its upper curvededge portion, and extending and enlarging rearwardly therefrom, with aninterior generally frusto-conical reflecting surface to the.

lip of the reflector.

In witnes whereof I hereunto alhx my signature this 23rd day of June,1925.

RICHARD GRAF.

